The nature of the Markush claim, the amendment to it in the invalidation proceeding and the method for the inventive step judgment

——Case of the Administrative Dispute over Invalidation of the Invention Patent between the Patent Reexamination Board v. Beijing Winsunny Harmony Science & Technology Co., Ltd., Daiichi Sankyo Company Limited[1]

[Judgment Highlight]

The compound claim written as a Markush Claim should be understood as a general technical solution rather than a collection of many compounds.

Amendment to the Markush Claim shall be allowed when a class of compounds or a single compound with new properties and effects is not produced due to the modification, however, individual cases that are an exception should also be considered.

The inventive step judgment of the compound claim written as a Markush Claim should follow the basic method for the inventive step judgment, that is, the “three-step method” stipulated in the Guidelines for Patent Examination. The unexpected technical effect is a contributing factor in the inventive step judgment. Normally it will be inappropriate to skip the “three-step method” and directly apply the unexpected technical effect to determine whether a patent application involves an inventive step or not.

  [Case Number]

  Supreme People’s Court 41 [2016], Administrative Retrial, SPC

  [Cause of Action]

  Administrative dispute over invalidation of an invention patent

  [Keywords]

  Invalidation proceeding, Markush Claim, Amendment, Inventive Step (Non-obviousness)

  [Relevant Laws]

  Paragraph 1, Article 31 of the Patent Law of the People’s Republic of China, Article 34 of the Detailed Rules for the Implementation of the Patent Law of the People’s Republic of China

  [Basic Facts]

  In the retrial of the administrative dispute over the invalidation of the invention patent (the administrative dispute over the invalidation of the patent under the “Markush Claim”) between the Patent Reexamination Board of the State Intellectual Property Office (hereinafter referred to as the Patent Reexamination Board) (the applicant), Beijing Winsunny Harmony Science & Technology Co., Ltd. (hereinafter referred to as Winsunny) (the respondent), and Daiichi Sankyo Company Limited (the third-party in the first instance); the last party is the holder of the patent titled “The preparation method of the pharmaceutical composition for the treatment or prevention of hypertension,” numbered 97126347.7 (i.e., the patent involved in the case). The patent claims are written in the form of a Markush Claim. Winsunny requested the Patent Reexamination Board for invalidation of the said patent on the ground that it involved no inventive step. On August 30, 2010, Daiichi Sankyo Company Limited made the following amendments to the claim: deleted “or ester” in the phrase “or its salt or ester which can be used for medicinal purposes” in Claim 1; deleted “alkyl with 1 to 6 carbon atoms” under the definition of R4 in Claim 1; and deleted the other technical schemes except carboxyl and Formula COOR5a under the definition of R5 in Claim 1. During the oral proceedings, the Patent Reexamination Board informed Daiichi Sankyo Company Limited that the deletion of “or ester” in Claim 1 was approved, but other deletions were unacceptable since they did not conform to the relevant provisions of Article 68 in the Detailed Rules for the Implementation of the Patent Law of the People’s Republic of China. Daiichi Sankyo Company Limited and Winsunny did not object to this. On January 14, 2011, Daiichi Sankyo Company Limited submitted a revised claim for replacement, in which the “or ester” in Claim 1 was deleted. The Patent Reexamination Board made Decision No. 16266 on the examination request for invalidation, in which it decided that Claim 1 of the patent involved in the case is non-obvious as compared to that in Evidence 1, has an inventive step and conforms to Paragraph 3, Article 22 of the Patent Law of the People’s Republic of China. Thus, on the basis of the revised version submitted by Daiichi Sankyo Company Limited on January 14, 2011, the patent right involved was upheld as valid. Opposing the decision, Winsunny initiated an administrative litigation. Beijing No.1 Intermediate People’s Court ruled that the Patent Reexamination Board had no error in the application of law for rejecting the revised text submitted by Daiichi Sankyo Company Limited on August 30, 2010, on the ground that it did not comply with Article 68 of the Detailed Rules for the Implementation of the Patent Law of the People’s Republic of China. Claim 1 of the concerned patent is non-obvious as compared to that in Evidence 1 and involves an inventive step. Therefore, the Court decided to affirm the Decision No.16266. Winsunny was not satisfied with the ruling and made an appeal. In the second instance, Beijing Higher People’s Court held that the Markush Claim is a special type of parallel technical solution, and that the revised text submitted by Daiichi Sankyo Company Limited on August 30, 2010 narrowed the scope of protection for the patent involved, which complies with Paragraph 1, Article 68 of the Detailed Rules for the Implementation of the Patent Law of the People’s Republic of China. The effect of a specific embodiment covered by the claim of the patent involved is similar to the technical effect of Embodiment 329 of the existing technology in Evidence 1. Claim 1 of the patent involved did not achieve the unexpected technical effect and therefore does not have inventive step.

  [Judgment Results]

  On April 1, 2011, the Patent Reexamination Board made Decision No. 16266 on the examination request for invalidation, in which it affirmed that the patent right involved is valid. Opposing the Decision, Winsunny filed an administrative lawsuit with Beijing No.1 Intermediate People’s Court, which decided on December 20, 2011 to uphold Decision No. 16266 made by the Patent Reexamination Board. Winsunny refused to accept the first-instance judgment and appealed to Beijing Higher People’s Court for revocation of the first-instance judgment and Decision No. 16266, and ordering the Patent Reexamination Board to make a new decision. On September 24, 2013, Beijing Higher People’s Court decided that the decision of the first instance and Decision No. 16266 made by the Patent Reexamination Board shall be revoked, and that a new decision shall be made by the Patent Reexamination Board on the examination request for invalidation. Opposing the decision, the Patent Reexamination Board applied for retrial to the Supreme People’s Court, which tried the case and ruled on December 20, 2017 that the decision of the second instance shall be revoked and that of the first instance shall be upheld.

     [Judicial Opinions]

  The Supreme People’s Court held that:

  I . Nature of the Markush Claim

  The Markush Claim is a special way of writing a claim to apply for chemical invention patents, i.e., a claim which applies for the identification of multiple parallel optional elements in one claim. The way a Markush Claim is written, is designed to solve the problem in the field of chemistry wherein many substituent groups cannot be summarized by a common upper-level concept. It has been considered as a structural expression rather than a functional expression. The Markush Claim requires the definition of parallel optional elements instead of additional claims, and all of its optional compounds have common properties and functions and a common structure, or that all the optional elements belong to the same compound recognized in the domain of the invention. Although the Markush Claim is written in a special way, it shall also comply with the provisions of the Patent Law and the Detailed Rules for the Implementation of the Patent Law. The Markush Claim has a very strong ability to generalize. Once authorized, the scope of patent protection will cover all compounds with the same structure, property or function, and the patentee’s rights and interests will be maximized. In essence, a patent right is the monopoly on a certain right, which means that the greater the scope of the rights enjoyed by the patentee, the more restrictions the public will be subject to. Therefore, from the point of view of fairness, the Markush Claim interpretation should be strict. No matter how many variables and combinations it includes, the Claim should be regarded as a general combination solution. The choice of a variable should generate a drug with the same effect – the choice of different molecular formulas should produce different drugs, but there should not be too much difference in the drug’s efficacy and the drugs should be mutually replaceable, and the expected effect should remain the same. That is the reason why the Markush Claim was created in the first place. Therefore, the Markush Claim should be regarded as a collection of the Markush elements rather than of many compounds. Normally the Markush elements should be understood as a class of compounds with common properties and functions, and would present themselves as a single compound only under certain circumstances. If it is determined that the compounds expressed under the Markush Claim are a collection of many compounds, it is inconsistent with the requirement of singularity. Therefore, it is incorrect for the court of second instance to decide that the Markush Claim is a parallel technical solution, and the decision should be corrected.

  II. Amendment to the Markush Claim in the Invalidation Proceeding

  The 2010 Guidelines for Patent Examination stipulates that during the invalidation request review stage, the amendment to the new invention and utility patent documents shall be limited to the claim and shall follow the basic principles: 1. The title of the original claim shall not be changed; 2. The scope of protection of the original patent shall not be extended as compared to the authorized claim; 3. The technical features shall not go beyond the original specification and claim; 4. Generally, technical features that are not included in the authorized claim shall not be added. However, the current method of amendment employed, aside from meeting the above principles, was specifically limited to the deletion of the claim, the deletion of the technical solution, the further limitation of the claim and the correction of an obvious error. Further limitation of the claim refers to the addition of one or more technical features recorded in other claims, so as to narrow the scope of protection. It can be seen that in the invalidation proceeding, the amendment to the patent documents can be conducted in multiple ways. However, there are many special issues in the examination of patent application for chemical inventions. For example, whether a chemical invention can be implemented needs to be confirmed by the result of the experiment; some chemical products need to be defined by means of parameters or preparation methods; and new properties and use of a chemical product do not mean changes in its structure or components. In view of the particularity of chemical inventions and given the fact that in writing the Markush Claim, the patent applicant has had the opportunity to put as many structures and formulas as possible into one claim in order to obtain the maximum scope of protection, the amendment to the Markush Claim should be strictly restricted in the invalidation stage. The amendment to the Markush Claim shall be allowed when a class of compounds or a single compound with new properties and functions will not be generated because of the amendment; however, individual cases that are an exception should also be considered. If a patent applicant or a patentee is allowed to delete any option of any variable, even if such deletion will narrow the scope of protection and will not impair the rights and interests of the public, there will be uncertainty in the possible new scope of rights protection, which will neither offer a stable expectation to the public nor maintain a stable patent right confirmation system. Therefore, the decisions made by the court of second instance are obviously improper and should be corrected.

  III. Method for Judgment of the Inventive Step of Markush Claim

 The judgment of the inventive step of Markush claim should follow the basic method for such judgment, that is, the “three-step method” stipulated in the Guidelines for Patent Examination. The unexpected technical effect is a contributing factor in judging the inventive step – it is a kind of backward judgment method, and it is special and does not have universal applicability. Therefore, only when a judgment on non-obviousness can be made based on the “three-step method” can a patent application be decided as involving an inventive step based on the unexpected technical effect. Generally, it would be inappropriate to skip the “three-step method” and directly apply the unexpected technical effect to determine whether a patent application involves an inventive step or not. As for the comparison of technical effects, in this case, the Patent Reexamination Board did not, in the invalidation proceedings, compare Embodiments 10, 17, 50 and 69 of Document 1 with those of the concerned patent and decide upon that comparison, whereas in the court of second instance, a direct comparison and decision was made, which obviously went beyond the scope of invalidation review. Such a practice does not conform to the provisions of the Administrative Procedure Law and relevant judicial interpretations and should be corrected. Winsunny, the requester for the invalidation, held that Patent Claim 1 involved in the case lacked the inventive step, and used Evidence 1 as the closest comparative document. When deciding whether Patent Claim 1 involves an inventive step or not, the Patent Reexamination Board and the court of first instance strictly followed the “three-step method,” and found that there are two distinguishing technical features between the compounds of Formula I in Claim 1 and the compounds of Formula I in Evidence 1. After analyzing the non-obviousness of the two distinguishing technical features, they believed that it was justified to declare the Patent Claim 1 involves an inventive step.